Collard Vanthournhout Florian, Remmelink Myriam, Polastro Laura, Ilzkovitz Maxime
Department of Internal Medicine, Jules Bordet Institute, Hôpitaux Universitaires de Bruxelles (H.U.B.), Université Libre de Bruxelles (ULB), Brussels, Belgium.
Department of Pathology, Jules Bordet Institute, Hôpitaux Universitaires de Bruxelles (H.U.B.), Université Libre de Bruxelles (ULB), Brussels, Belgium.
Eur J Case Rep Intern Med. 2025 May 9;12(6):005349. doi: 10.12890/2025_005349. eCollection 2025.
This case highlights the diagnostic complexity of pulmonary granulomatosis in oncology patients, especially when treated with targeted therapy.
We report the case of a 46-year-old female with metastatic HER2-mutated breast cancer who had received multiple lines of HER2-targeted therapies. The patient presented with suspected lung and mediastinal lymph node progression, despite a good response at other affected sites. A lymph node biopsy revealed non-necrotizing pulmonary granulomas, with negative microbiological testing. Further evaluations showed highly elevated anti-PR3 autoantibodies, while angiotensin-converting enzyme (ACE) and calcium levels remained within the normal range. Pulmonary function tests confirmed a restrictive syndrome. Nasal fibroscopy identified chronic sinusitis with massive nasal polyposis, without renal or cutaneous involvement. High-dose corticosteroid therapy was initiated, leading to a favourable response. Based on the clinical presentation, radiological findings, and pathological features, we concluded that the granulomatosis was related to HER2-targeted therapy.
This case highlights that both an underlying malignancy and specific drugs-such as HER2-targeted therapy-can occasionally contribute to granuloma formation.
Differentiating pulmonary granulomatosis is challenging in oncology patients.HER2-targeted therapies can induce non-necrotizing lung granulomatosis.
本病例突出了肿瘤患者肺部肉芽肿病的诊断复杂性，尤其是在接受靶向治疗时。
我们报告了一例46岁的HER2突变转移性乳腺癌女性患者，她接受了多线HER2靶向治疗。尽管在其他受累部位反应良好，但该患者出现了疑似肺部和纵隔淋巴结进展。淋巴结活检显示非坏死性肺肉芽肿，微生物检测为阴性。进一步评估显示抗PR3自身抗体高度升高，而血管紧张素转换酶（ACE）和钙水平仍在正常范围内。肺功能测试证实为限制性综合征。鼻纤维镜检查发现慢性鼻窦炎伴大量鼻息肉，无肾脏或皮肤受累。开始高剂量皮质类固醇治疗，取得了良好反应。根据临床表现、影像学检查结果和病理特征，我们得出结论，肉芽肿病与HER2靶向治疗有关。
本病例突出表明，潜在恶性肿瘤和特定药物（如HER2靶向治疗）偶尔都可能导致肉芽肿形成。
在肿瘤患者中鉴别肺部肉芽肿病具有挑战性。HER2靶向治疗可诱发非坏死性肺肉芽肿。
